Pneumatic compressor.



No. 800,765.. PATENTED OCT. 3, 1905. L. H. ROGERS.

PNEUMATIC COMPRESSOR.

APPLIOATION FILED DEG.29. 1904.

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V v A 20 amour LEBBEUS H. ROGERS, OF NEW YORK, N. Y.

PNEUMATIC COMPRESSOR.

Specification of Letters Patent.

Patented Oct. 3, 1905.

Application filed December 29, 1904. Serial No. 238,821.

To (all whom, it nut/y concern.-

Be it known that I, LEBBEUs I-I. ROGERS, of New York, State of New York,have in vented a new and useful Improvement in Pneumatic Compressors,which invention is fully set forth in the following specification.

This invention relates to pneumatic compressors, especially to rotaryair-compressors in which considerable oil is used in and about theirmoving parts, and to means whereby such oil and parts may be warmed whenthe surrounding temperature is below that necessary for effectiveoperation of the compressor.

Air-compressors of the type above referred to find application inconnection with air-brake systems on street-cars and railwaytrains,where they are used to compress air in the main air-reservoir. Incertain forms of such compressors oil is used within the compressor,which in cold weather is apt to congeal during periods of rest. Whilethe compressor is in operation, however, sufficient heat is produced bythe friction of the pistons and other movable parts to maintain the oilin the compressor in a fluid state even in severe cold weather; but whensuch compressors are used in connection with automatic controllers whichstopthe operation of the compressor when a predetermined pressure isreached in the compressed-air reser voir the oil in the compressor maybecome viscous and congeal during the time of inaction of the compressorin severe cold weather. In the case of street-railway cars, which arerun into a cold barn for several hours during the night, thisobjectionable phenomenon frequently occurs. By morning the oil becomestoo viscous and often congealed to,

permit the compressors to be immediately used or permit the cars to berun onto the road for service. It therefore becomes nec essary for eachcar carrying a compressor to be detained in the morning in the coldestweather till the men tending the cars can warm up each compressor by aidof torches or lamps to the point where the congealed oil becomes fluid,after which friction of the moving parts during operation of thecompressor will keep the oil in working condition.

To avoid the above objections and reduce the time and amount of laborrequired in putting such compressors into operation during periods oflow temperature, I have de-,

vised means whereby heat may be instantly applied to the interior of thecompressor to raise the temperature within the same to a propertemperature for its operation, and this is accomplished by placingwithin the interspaces of the piston-carrying drum suitable heatingdevices, but preferably electric heating devices, as hereinafterdescribed, and specifically pointed out in the claims.

In the accompanying drawings I have shown, for the purpose ofillustration, the best embodiment of the invention known to me, in whichFigure 1 is a vertical section through an air-compressor provided withmy improvement. Fig. 2 is a vertical cross-section of the same, taken onthe line 2 2 of Fig. 1 looking toward the right, while Fig. 3 showsdiagrammatically a plurality of heaters controlled by a single switch.

Referring to the drawings, 1 is the outer casing of rotaryair-compressor of the type described in my copending application, SerialNo. 223,913, filed September 9, 1904. So much of the same is hereindescribed as will suffice to show the connection of the inventiontherewith. Casing 1 is preferably provided at one end with an integralhead 2; at the other end with a removable head 3, which is secured tothe casing in any wellknown or suitable manner. Projecting from eachhead are bearings 4 5 for supporting a revoluble shaft 6, which makes atight joint with the bearings 4 and 5 by stuffing-boxes 7 8. Fast toshaft 6 is a drum 9, and fast to the ends of drum 9 are rings 10 11,which partially close the ends of the drum and are secured thereto byscrews 12. At the lefthand end of the cylinder 1 is a plate 13, securedto the cylinder and provided with openings 14, which communicate with anoilreceiving space 15, formed in the integral end of the. cylinder.

In Fig. 2 is shown an oil-supply reservoir 16, which is adapted todeliver oil through pipe 17 to a channel 18 in the head 2, leading tospace 15, and thence through openings 14 to portions of the interior ofthe drum 9. This drum is divided longitudinally into one or morecompression-chambers 19, having parallel walls which guide theair-compressing pistons 20, as they are made to reciprocate by anysuitable means, such as by cams 21, at the end of each of the pistons20, running in cam-grooves 22 23, eccentric to the axis of the cylinder9. The rotation of the shaft 6 causes the drum 9 to rotate, carryingwith it the pistons 20, whose cams 21 travel .Within easy reach of theattendant.

in cam-grooves 23, causing the pistons during one half-revolution of thedrum to draw in air at 24 and compress it during the otherhalf-revolution through exit 25. The space back of the pistons and alsothe quadrangular spaces 27 between the piston-channels are filled withoil supplied from tank 16. When the temperature of the oil lowerssufficiently, as it is apt to do in. cold weather, it becomes viscousand even congeals, interfering with the movement of the pistons, and itis for the purpose of avoiding the usual delay in heating up the wholecompressor that I have provided the piston-carrying drum With means forlocally heating the oil in. the drum, and to this end I preferably placean electric heating-coil 28 in each of the spaces 27 and connect themeither in. series or parallel with insulated conductors 29 and 30, whichare in metallic contact with slip-rings 31 and 32, respectively. Theserings are insulated from the shaft 6 by non-conducting material, such asmica or like material, (shown at 33 and 34.) Brushes 35 36 connect therings and the coils connected to them with a source of current, such asa battery, or to the mains. When these compressors are located upon anelectric car or train, the brushes are connected to a switch WVhere anumber of cars are in a single shed or barn, temporary electricconnections may be made from each compressor to a central switch,whereby all the heaters may be simultaneously operated by one person. InFig. 3 there is shown diagrammatically two such compressors 1 1, eachlocated beneath its car and temporarily connected through suitable leadsfrom switch 37 to a central switch 40, adapted to close a circuitthrough the heating coils and mains 38 39, which latter are to belocated in the car shed or barn in convenient proximity to the cars. Onclosing switch 40 and any one or all of switches 37 one or all thecompressors maybe heated.

The operation of the heating device will be readily understood from thepreceding description and drawings. During the cold weather the carsremain during the night in cold barns or even in the open, during whichtime the oil. in the compressors is often chilled to a degree whichrenders it viscid and even semicold. Before running the cars out for theday it was necessary heretofore for the attendant to warm eachcompressor by a torch or lamp to render the oil sufliciently fluid forthe proper working of the compressor. By aid of. the abovedescribedimprovement it is only necessary to turn on the current through theheating-coils by means of an electric switch, which may control thecurrent to one or many compressors. Heat is thereby instantly applied toall the compressors simultaneously. This results in a great saving oftime and labor during the cold weather each time the cars are startedout for the days run:

Although I have described this invention in relation to rotary pneumaticcompressors, yet it is equally applicable to pumps and other forms ofcompressors where the parts run in. oil and to suchdevices where theviscosity of the oil is to be overcome by heat, and I do not limit myinvention to the precise construction and arrai'igements shown, aschanges in construction or arrangement may be made without departingfromthe spirit of my invention.

that is claimed is 1. I11 combination, a pump, an oil-supply reservoirfor the same, and means within the pump for heating the oil.

2. In combination, a pump, an oil-supply reservoir for the same, andelectric heating means within the pump.

3. In a pump, a revoluble piston-carrying drum and heating means withinthe drum.

4. In combination, a pump having oil-receiving spaces therein andheating means within the pump.

5. In combination, a compressor-pump having an oil-receiving spacetherein and electric heating means in said. space.

6. In a pump, a revoluble piston-carrying drum, electric heating meansin the drum, leads located in the axis of the drum and connected to saidheating means, and contactrings connected to said leads.

7. In a pump, a revoluble piston-carrying drum, a shaft supporting thesame, electric heating means in the drum, leads .in the shaft in circuitwith said heating means, and slip-rings on said shaft connected to saidleads.

8. In an air-compressor pump, a rev0 luble piston carrying drum, oilreceiving spaces in said drum, electric heating means carried by saiddrum, and means for connecting said heating means with a source ofelectric current.

9. In an air-compressor pump, a revoluble piston-carrying drum havingoil-spaces within the same, electric heating-coils in said spaces, andmeans for connecting said heating means with a source of electriccurrent.

10. In an aireompressor pump, a revoluble piston-carrying drum havingoil-spaces within the same, a shaft for rotating said drum, electricheating means in said oilspaces, leads in said shaft connected inparallel with said electric heating means, and slip-rings on said shaftconnected to said leads.

11. In a system of heating pneumatic compressors on cars, a plurality ofsaid compressors, electric heating means within each compressor, asource of current-supply, and means for connecting the same with each ofsaid heaters, and a single switch for controlling current to all theheaters.

I; 12. In combination, a pneumatic c0mspecification in the presence oftwo subscribpressor for cars, electrlc heatlng means wlthlng Witnesses.

in the compressor, a source of current-supply 1 w means for connectingthe same with saici LILBBLUS ROGERS v 5 heater, and a switch on the carfor control- Witnesses: a

ling current to said heater. L. HARDING ROGERS, Jr.,

In testimony whereof I have signed this DWIGHT MCDONALD.

